[ RadSafe ] Sickening Solar Flare

[Hansen, Richard]

Bernard,

There values given for the LD50/60 vary somewhat in the literature. They are
often given as about 300-350 rad (or cGy) with little or no medical care and
about 450-500 rad with medical care. Modern medical care can raise the
LD50/60 even higher.


From
Medical Management of Radiological Casualties Handbook
Second Edition, April 2003
Armed Forces Radiobiology Research Institute
http://www.afrri.usuhs.mil
Pg 8.

The severe radiation sickness resulting from external
irradiation and its consequent organ effects is a primary
medical concern. When appropriate medical care is not
provided, the median lethal dose of radiation, the LD50/60
(that which will kill 50% of the exposed persons within a
period of 60 days), is estimated to be 3.5 Gy.
...
Modern medical care dramatically improves the survivability
of radiation injury. Nearly all radiation casualties
have a treatable injury if medical care can be made
available to them.

From
Dose-Rate Dependence of High-Dose Health Effects
in Humans from Photon Radiation
with Application to Radiological Terrorism
D. J. Strom
January 2005
http://www.pnl.gov/bayesian/strom/pdfs/Strom2005E_PNNL-15005.pdf

... the LD50/60 increases from about 3 grays (300 rads) when given at very
high dose rates to over 10 grays (1,000 rads) when given at much lower dose
rates over periods of several months.
...
This paper uses 1 Gy = 100 rads = 150 R as a conversion, that is, 1 R = 2/3
rad.
...
The LD50/60 value is discussed at length by Lushbaugh et al. It is is
constrained to pass through a value of 450 R at 1.5 R/min and has a K of
0.65 (R/min)^(1/3) 
Lushbaugh CC, KF Hübner, and SA Fry. 1982. "The Impact of Estimates of Human
Radiation Tolerance upon Radiation Emergency Management." Chapter 4A in The
Control of Exposure of the Public to Ionizing Radiation in the Event of
Accident or Attack. Proceedings of a Symposium Sponsored by the National
Council on Radiation Protection and Measurements, April 27-29, 1981

From
The Medical NBC Battlebook USACHPPM Tech Guide 244
May 2000

"The median lethal dose of radiation that will kill 50 percent of the
exposed persons within a period of 60 days, without medical intervention
(designated as LD50/60), is approximately 450 cGy. Medically, other figures
of interest are the dose that will kill virtually no one, (LD5), and the
dose that will kill virtually every one (LD95). Approximations of those
doses are within the ranges 200-300 cGy (free in air) and 600-700 cGy (free
in air), respectively.


Rick Hansen
Senior Scientist
Counter Terrorism Operations Support
Bechtel Nevada

-----Original Message-----
From: Bernard Cohen [mailto:blc+ at pitt.edu] 
Sent: Thursday, February 10, 2005 8:26 AM
To: Maury Siskel
Cc: RadiatSafety
Subject: Re: [ RadSafe ] Sickening Solar Flare

Is this piece correct in saying that LD-50 is 300 rem? It used to be 450 
rem.